Moisture and nutrient management strategies influence the photo-thermal environment in cotton-wheat cropping system

Although, crop productivity is determined by several factors like photo-period, moisture and fertility, but it is primarily influenced by temperature. Increasing water scarcity due to high evapo-transpiration is a major concern for crop production. Therefore, a field experiment was planned to evaluate the response of varied irrigation and fertilization levels on agrometeorological indices of cotton-wheat cropping system at the Research Farm, Department of Soil Science, Punjab Agricultural University, Ludhiana for two consecutive years i.e. 2019-2020 and 2020-2021. Higher heat indices were resulted from longer phenophases under well fertilized and watered conditions. Cotton irrigated through subsurface drip at 100% ET_c along with100% RDN and foliar application of nutrients i.e. 2% KNO₃ (4 times) & 1% MgSO₄ (2 times) exhibited higher heat indices i.e. growing degree days, helio-thermal units, photo-thermal units, relative temperature disparity and heat use efficiency over all other treatments, to reach maturity. On the other hand, wheat crop that received 100% irrigation through sub-surface drip irrigation and fertilization along with the residual effect of equivalent quantity of soil applied 2% KNO₃ and 1% MgSO₄, to cotton experienced higher heat indices than to other treatments.